<?php 
class ConnDB{
    private $conn;
    public function __construct($host,$user,$pwd,$dbname,$charset){
        $this->conn = @mysql_connect($host,$user,$pwd) or die('数据库连接失败！'.mysql_error());
        //选择数据库
        @mysql_set_charset($charset);
        @mysql_select_db($dbname) or die('数据库不存在！'.mysql_error());

    }
    //执行sql语句，如果是select语句，就返回查询结果集数组，否则返回true或false，
    function query($sql){   
        $sqltype = strtolower(substr(trim($sql),0,6));
        $result = mysql_query($sql,$this->conn) or die('查询失败'.mysql_error());
        //定义二维数组用于存储select语句的查询结果
        $callback_array = array();
        //判断sql语句的类型，如果是select语句
        if("select" == $sqltype){
            //如果select
            if($result == false){
                return false;

            } else if(0 == mysql_num_rows($result)){
                return false;
            } 
            /*else if(1 == mysql_num_rows($result)){
                return mysql_fetch_array($result);
            } */
            else 
                while ($result_array = mysql_fetch_array($result)){
                    array_push($callback_array,$result_array);

                }
                return $callback_array;

    }
        else if('update' == $sqltype || 'insert' == $sqltype || 'delete' == $sqltype){
            return $result;
    }

    }
    function __destruct(){
        mysql_close($this->conn);
    }


}




 ?>